The mission of the Neural and Developmental Toxicology Core is to serve as a focus for mechanistic research in neurotoxicology and developmental toxicology. The prime directive of this core is to elucidate mechanisms of selective vulnerability as related to toxicant effects on specific brain cells and regions. This core is directed by Dr. Ken R. Reuhl, Ph.D. with Dr. Herbert E. Lowndes, Ph.D. serving as co-director. This core is comprised of approximately 10 full-time faculty with diverse research expertise in behavioral, cellular and molecular indices of nerve cell injury and degeneration. Vulnerability has been a consistent theme for this core and acts as a focal point for 3 research affinity groups: Developmental Neurotoxicology, Neural Metabolism and Models of Neuronal Disease. Subdivision of the Core into affinity groups significantly improved organization and promoted hypothesis-directed research. Each affinity group addresses specific aims related to that groups research focus; e.g., the Developmental Neurotoxicity group explores the involvement of toxicant-induced disruption of cytoskeletal proteins, adhesion molecules and axonal guidance cues in mediating brain cell dysgenesis. During the present funding period (1993-1997), there have been several changes in personnel; although two members left the program, four faculty have been added with expertise in developmental, behavioral and chemical toxicology. Core members have been highly productive publishing more than 80 papers many of which resulted from inter-and intra-Core collaborations. Plans for program growth and future directions include continued research collaboration among Center and non-Center members, with selective vulnerability as the focal issue. Molecular techniques will be emphasized to facilitate mechanistic explorations. The Core leadership recognizes the importance of whole animal corroboration of molecular findings and, therefore, proposes inclusion of systems and behavioral analyses in future studies.